Camozzi Pneumatics Manual

CIRCUIT TECHNIQUE

The sequencer

The preliminary analysis required will depend on the method adopted for the realization of the circuit, as regards

to the feeding of the air supply to the limit switches that generate blocking signals.

In certain cases, the circuit can be simplified by repeatedly using at least two pneumatic functions, a 3/2-way

memory valve and a logic AND function. These elements can be connected and integrated in a single device –

sequencer

With the sequencer device, the blocking signals or their duration are no longer determinant.

Figure 97

Pos. 1

: a

3/2-way

memory valve is drawn in the

open

position and fed by the main compressed air network,

its output is defined as

. This output allows the advancement of the cycle or to feed the Start button with

compressed air.

Pos. 2

: the output

is connected to an

AND

function in parallel. The output of this function is only activated in

the presence of signal

from the first limit switch actuated after the start of the cycle.

Pos. 3

: the signal

is now present, the output of the

AND

function is active and operates the memory valve of

the successive sequencer, which generates output

by opening. This output, in addition to being used as a pilot

signal for valves in the circuit, closes the

3/2-way

memory valve which generated

. Closing the memory valve,

output

is exhausted and consequently also the pilot signal

of the memory valve that generated output

Fig. 97

Cil. "A"

Cil. "B"

a0 a1

b0 b1

I.C.

1 2 3

5 4

6 1

U1 * b0 * I.C. = A+ Fase 1

U1 * a1 = B+ Fase 2

b1 = S2 = U2 = B- Fase 3

U2 * b0 = A- Fase 4

U2 * a0 = S3 = U3 = B+ Fase 5

U3 * b1 = S4 = U4 = B- Fase 6

U4 * b0 = S1 = U1

I.C. A+ / B+ / B- / A- / B+ / B-

U1 U2 U3 U4

Fig. 96

Finally, we report the initial condition at completion of stroke

U4 * b0

The sequence has terminated and awaits a new Start command from the

I.C.

valve

187

CAMOZZI

CIRCUIT TECHNIQUE